Some wireless communication systems allow users of mobile devices to participate in voice conversations and video conferences, to send and receive data and media files, to send and receive Short Message Service (SMS) messages, or the like. Some users may require broadband communications, for example, in order to rapidly send and receive large files or in order to experience high-quality video playback.
The per-user communication demand for broadband data is increasing due to a combination of factors including, for example, growing size of raw data content (e.g., proliferation of video traffic), more data being generated due to faster computation capabilities, and increased connectivity that encourages sharing data with more users.
To support the growing communication demand for ever-higher data rates requires ever-wider portions of Radio Frequency spectrum per user. However, spectrum is a precious resource, and is often strictly regulated or difficult to find. Therefore it is important to provide spectrally efficient techniques that can maximize the data rates and number of users per unit of spectrum.